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How much power can the gearbox take on a tdi?

Discussion in 'A8/S8 forum' started by PalmerA8, Feb 20, 2014.

  1. PalmerA8
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    PalmerA8 Member

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    Looking to get my 4.2 remapped. Hoping for over 400bhp and god knows what torque. Anyone know what the tip box is rated too? Is this the same gearbox as in the S8 etc?
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  2. Gavin0478
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    Gavin0478 Member

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    Well my Q7 (my11) has the later spec 340 bhp 4.2 and the 8 speed zf gearbox.

    It has had both the engine remapped and the gearbox remapped by DMS and is running 400 bhp ish and 900 nm ish with no issues.

    It is as standard torque limited in the lower gears and do remember that it is 4x4 so will not spin off power and relieve any extra strain on components like that.

    One thing i will say is that there is basically no need for kick down as the torque in any gear just fires you off even when you are trundling down the autobahn at 60-80.

    Have you got any other mods.
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  3. PalmerA8
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    PalmerA8 Member

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    Yeah mines the older 6 speed box.

    No other mods but i want a cat / dpf delete before the remap. Maybe knock a silencer out too :-D
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  4. cocain
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    cocain RAA RAA like a dungeon dragon!

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    I'mlookingto get mine remapped within the next fortnight :)
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  5. BahnStormer77
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    BahnStormer77 BahnStormer

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    It's the torque that can break gearboxes, not the power - yours would almost certainly have more toqrue than even the S8 gearbox!

    As Gavin has pointed out - the standard torque is limited to protect components (mostly the clutch) at lower revs, when the engine is under load and the clutch is engaging.

    I'm not sure how these auto 'boxes react as most of my diesel tuning has been with smaller manual gearboxes.
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  6. cocain
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    cocain RAA RAA like a dungeon dragon!

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    I got my remap from AMD in Thurrock, Essex. It's right next door to lakeside shopping centre.
    The cost was £499. I was quoted £250 by someone else but I have used AMD in the past on my A4 so I went with them.
    I will try and attach the graph for you.

    Before remap
    Power 352.6hp @ 3716 rpm
    Torque 523.1 lb ft @ 3155 rpm

    After remap
    Power 390.2hp @ 3559 rpm
    Torque 653.2 lb ft @ 2415 rpm


    https://dl.dropboxusercontent.com/u/...emap 001.jpg

    So far so good
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  7. Gavin0478
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    Gavin0478 Member

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    Thats a High starting figure as i thought they were either 326 early or 340 later bhp's for the V8
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  8. BahnStormer77
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    BahnStormer77 BahnStormer

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    I've always been DEEPLY skeptical of AMD's dyno plots... I've had 4 dyno runs there, with 2 different cars (admittedly only at their old Bicester site), but they always seemed to come up with massively inflated transmission losses, so they actually quote very mediocre ATW power, but then hand you the dyno plot that says you've got some crazy flywheel power readings.... which is what is normally on the graph.

    e.g. a stock Mk3 Golf GTI (2.0 8v NA), that should be kicking out 115PS was dyno'd at 138bhp... I had a fairly hefty amount of work done to it as it was "far from fast", they were then quoting 155bhp... it still didn't feel that quick.... I went to another RR session a week later, only to be quoted "115bhp and it is running VERY lean" (the car still felt as fast as it had done when I got it back from AMD)... I took it back to AMD to be checked over and dyno'd again and was told it was all fine and still well over 150bhp. I haven't been back to AMD since, but we eventually found the problems (collapsing vacuum hose and the FPR couldn't cope with the fuelling requirements due to the increased airflow + high lift cams), sorted it out and got it to the point where I was consistently getting it dyno'd at around 150bhp at various other RR's, but it felt like a fundamentally different (MUCH faster) car compared to the "155bhp" car that AMD handed over to me and insisted was a genuine 155bhp.

    Note that was all 5-10 yrs ago and at their old site, but it has flavoured my view on them since.
    Last edited: Mar 21, 2014
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